Social ERM (employee relationship management) software provider Yammer has raised $85 million in new funding, just a short time after the company pulled in $17 million to expand its services.

The new cash infusion will be used to hire more sales and engineering staff members and to improve the company’s advertising. It’s also believed that some of the cash could be used to acquire other startups in the same space.

Yammer managed to triple sales growth in 2011 after acquiring 4 million users for its social networking service.

Best described as “Facebook for company’s” the platform provides each employee with a profile and a wall. Users can exchange ideas and even follow each other on Facebook.

The cash infusion was needed as other company’s such as Jive have jumped into the space. Jive revenues surged by 53% last quarter, giving Yammer reason to expand quickly and claim dominance in the space.